Fracture behaviour in tension of viscoplastic porous metallic materials saturated with liquid

The present work extends the investigation which has been initiated in Parts I and II of this study (Martin, C.L., Favier, D., Suéry, M., 1997a. Viscoplastic behaviour of porous metallic materials saturated with liquid, part I: constitutive equations. Int. J. Plasticity 13, 215–235; Martin, C.L., Favier, D. Suéry, M., 1997b. Viscoplastic behaviour of porous metallic materials saturated with liquid, Part II: experimental identification on a Sn–Pb model alloy. Int. J. Plasticity 13, 237–259) to the tensile behaviour of viscoplastic porous metallic materials saturated with liquid. Simple tensile experiments together with ring extension tests are carried out to study the fracture behaviour of this class of material. Ring tests consist in applying an internal pressure on a specimen with a ring shape. A Sn–Pb model alloy with a dendritic microstructure is used to characterise the behaviour of the material up to fracture. The liquid presence is accounted for to derive the intrinsic behaviour of the solid skeleton. The collected data are then incorporated in the model framework presented in Part I. A simple modification of the model allows the treatment of the strong asymmetry between tension and compression which is exhibited by these materials.